What Is the Bitcoin Halving?

Imagine running a business where your main source of income will be cut in half on a known date. Not an estimate: the date has been public since before you opened, and it will happen again four years later, and four years after that. Nobody can postpone it. Nobody can lobby for an exception. Your only choices are to become more efficient, to earn more from other sources, or to close.

That is the position of every Bitcoin miner on earth. The event that cuts their income is called the halving, and the most recent one happened at 12:09 in the morning, Coordinated Universal Time, on April 20, 2024.¹

What Gets Cut in Half

Bitcoin's ledger grows by one block about every ten minutes. Whoever adds a valid block is paid in two ways: transaction fees from the people whose payments are included, and a fixed amount of brand-new bitcoin called the block subsidy. The subsidy is how every bitcoin in existence was first created.

Every 210,000 blocks, the software cuts that subsidy in half. It started at 50 bitcoin per block in 2009, fell to 25 in November 2012, 12.5 in July 2016, 6.25 in May 2020, and 3.125 in April 2024.² In practical terms, the network went from creating about 900 new bitcoin a day to about 450 overnight. Added up, that halving schedule is where the 21 million limit comes from, which a separate article walks through.

No meeting decides any of this. There is no announcement, no vote, and no committee. At block 840,000, every computer running Bitcoin simply began rejecting any block that paid its miner more than 3.125 new coins. The next halving comes at block 1,050,000, expected around April 2028.

What Happens to the Miners

Miners run specialized machines that use electricity to compete for the right to add each block. Their costs do not halve when their subsidy does. So at every halving, the least efficient machines, the ones whose power bill now exceeds what they earn, are switched off.

You might expect that to slow the network down. It does not, because of a second rule built into Bitcoin. Every 2,016 blocks, roughly every two weeks, the network measures how fast blocks have been arriving and adjusts the difficulty of the puzzle so that they keep coming about every ten minutes.³ When machines unplug, the puzzle gets easier for the ones that remain. When more machines join, it gets harder. Four halvings have come and gone, and the network has kept producing blocks through every one of them.

The halving also shifts weight toward the other half of a miner's income. The very block that triggered the 2024 halving paid its miner about 37.6 bitcoin in transaction fees, more than ten times the new subsidy, because a rush of activity that night made block space briefly in high demand.¹ That was an unusual night. It was also a preview of the long-term design.

Does the Halving Make the Price Go Up?

This is the claim you will hear most often, so it deserves a careful answer. The argument goes like this: if demand stays the same while the flow of new coins is cut in half, the price should rise. And each of the first three halvings was followed, within a year or two, by a large rise in Bitcoin's price.

There are good reasons to hold that pattern loosely. Four halvings is a very small sample. The date of every halving is known years in advance, so anyone who believes it will move the price can act on that belief early, which is how markets tend to absorb predictable events. And in the years between halvings, Bitcoin's price has also fallen by more than half more than once. Its supply schedule is fixed. Its price is not, and nothing about the halving changes that.

What the halving reliably does is narrower and more certain: it reduces the amount of new supply entering the market. After the 2024 halving, Bitcoin's supply grows by under 1 percent a year, less than gold's. After 2028 it will be around 0.4 percent. That is a fact about issuance, not a forecast about price.

What Happens When the Subsidy Runs Out?

Each halving makes the subsidy smaller, and around the year 2140 it reaches zero. From then on, miners will be paid by fees alone.

Whether fees will be enough to keep the network as secure as it is today is a genuine debate, and it would be dishonest to pretend otherwise. Some researchers worry that a shrinking subsidy could leave the network with a thinner security budget, particularly if fee demand is weak. Others point out that the change is gradual, that more than a century remains, and that fees naturally rise as more people compete to settle payments on a network that cannot be expanded at will. Both sides agree on one thing: the transition was built into the design from the first day, and nobody can quietly change it to make the problem easier.

A Schedule Anyone Can Read

The most unusual thing about the halving is not the cut. It is that everyone knew it was coming. The supply schedule of the US dollar is set by policy and can change at the next meeting. The supply schedule of gold depends on what miners find and what prices encourage them to dig. Bitcoin's was published in 2009 and has run exactly as written, four times so far.

Whether a money with a fixed, public schedule turns out to be better than one managed by experts is a question each person has to weigh. Why it is even a question, and what happens to ordinary families when the schedule is set by someone else, is where the free first lesson begins.